Piston packing-ring.



E. W. PETTER. -PISTON PACKING RING. APPLICATION FILED AUG. 4. 1908.

Patented July 27, 1909.

ATTORNEYS.

ERNEST W. PETTER,. OF LONDON, ENGLAND.

' PISTON P AQKING-RING- Specification of Letters Patent.

Patented Jul 27, 1909..

Application tiled Augusta, 1908. Serial No. 446,960.

To all whom it may concent:

Be itknown that I, ERNEST Wmnouormr Perms, mechanical engineer, a subject .of

I the King of Great Britain, residing at London, Enfgla'nd, have invented certain new .1

and use ul' Improvements in Piston Packing-Rings, of which the following is a specification. r y

This invention relates to improvements in piston rings or expansion rings for use in steam engines, internal combustion engines and umps or for analogous purposes and has or itsobject the provision of, a ring which shall overcome many of the drawbacks anddisadvantages to which rings as heretofore constructed are liable.

In piston rings of the t pe commonly used for the cylinders o reciprocating steam engines, reciprocating pumps, internalcombustion engines, and other similar machinery, the ring is usually of some suitable and elastic metal such as phosphor bronze 'or cast iron and is turned cylindrically of somewhat larger diameter than the bore of the cylinder. It is then usually cut across and a portion of the metal re-.

moved at the place where the cut occurs so as to permit the vring to close up to the correct dlameter of the cylinder, but when it is thus closed up it is not a true circle on the outside. It is, therefore, held in this closeda true circle of the exact diameter of the.

up position in a chuck, and turned or groundagain on the outslde so as to be made cylinder, and in addition to this when released from the chuck it has the property of being able to spring open or exert radial pressure outward. Now, if the ring be the same thickness all around the outward pressure exerted will not be evenly distributed, but will be excessive at the part where the ring is cut open and least at the'part'opposite to this. One method of overcoming this drawback has been to turn the ring eccentrically on the inside so as to make it thinner at the part whereit is cut open and thicker at the opposite part; but a ring made according to this method has manydisadvantages of which the following are the ring.

some :-(1) There is excessive side wear on (2 The rin is liable to cut and wear the piston and cy inder. (3) The ring is liable to jump over its stopfor example if a small pin or peg is used. There are other disadvantages which it is not neces-' sary to refer to here in detail.

Now my invention is (inter alia) designed backs in such rings as heretofore constructed, and in order-to eifect thisI cut'or turn or form the interior surface of my ring with an eccentric groove or grooves therein in such-a way as to regulate the mass of metal at various points of the ring so that the greatest mass is at the point farthest distant from the split or division and the least mass at the said point of division and nevertheless so as not to interfere with the radial thickness of the .ring on one or both lateral surfaces thereof.

. My invention may of course be applied to other rings than piston rings where suitable, for instance it may be applied to other expansion rings such for example as are employed as packing rings in other types of engines besidesreciprocating engines.

I give the following as an example of one.

mode of carrying my invention 1nto practice in the case of a piston ring, the same being split or divided as usual. On the interior surface (2'. e. the inside circumference) of the piston ring I cut or turn or form a groove medially on the surface and of a width sa about half (or more or less) the widtho the said interior surface the said groove being of graduated or varying depth;

the greatest depth being at the oint where the ring is cut or divided an from this point of greatest de th the groove grows shallower on each si e until at a point opposite the split or division the groove 1s at its shallowest or there is no groove at all.

.The annexed drawing illustrates an example of a piston ring according to this invention; Figure 1 beinga plan viewof the ring; Fi 2 a vertical plane section through the mid le of the ring; Fig. .3 a section on line B-B of Fig. 2; and Fig. 4 a section on line A-A of Fig. 2. w

The ring Y according to thisinvention, as illustrated, is machined inside and outside concentrically and is provided with an eccentric groove Z on the interior circumference of the ring so as to leave the lateral surfaces X X of the ring intact, obtaining at the same time a variable section of the radial thickness of the ring Y.

As an example of one mode of manufacture of this ring I may proceed as follows A cylindrical tubular casting is made of sufficient length to form a number of the piston to overcome the said disadvantages or draw- .on its outside to a circumference larger than the internal diameter "of the cylinder in which it is intended to use the rings, this casting is then divided up into the individual piston rings and each of the latter is then split and the split ring chucked and, turned (machined) again to the final diameter to be given same and then it has the aforesaid; eccentric groove (or'groove's) cut in the sur face ofthe interior circumference thereof according to this invention. Or, if desired, the eccentric groove or grooves-may be'forineql in the surface of the interior circumference of said ring before the'exterior is turned or finished or concurrently therewith and either before or after. splitting the ring or before or.

after the aforesaid casting is divided up into the individual rings, asd'e sired.

What I olairn is:-

1. An expansion-ring having a split therethrough and a'taperin groove in its inner face and in'the plane 0 the expansionface with a crescent-shaped empty groove extending nearly completely around said inher 'face, said; ring being split through at the eep st, part Qf g oov In witness. whereof I have I hereunto set my hand in presence of two w1tnesses.- I

. Witnesses:

H, D. Jamison, F. R N

ERNEST W. PETTERQH 

